United States Commemorative Postage Stamp, Progress in Electronics, Marconi Spark Coil, Marconi Spark Gap, Gugliemo Marconi, Inventor of Wireless Marconi,
Issued July 20, 1973, in New York, New York,
First Day of Issue Cover, FDC, Artmaster Engraving Cachet, Unaddressed,
Cover in Removable Transparent Poly Sleeve and Mailed With Protection,
Made in the USA
Genuine First Day of Stamp Issued Cover Cancelled on the First Day of Issue Date by the U.S. Postal Service,
